1 files changed, 114 insertions, 0 deletions
diff --git a/arch/riscv/kernel/irq.c b/arch/riscv/kernel/irq.c
new file mode 100644
index 0000000000..9cc0a76692
--- /dev/null
+++ b/arch/riscv/kernel/irq.c
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2012 Regents of the University of California
+ * Copyright (C) 2017 SiFive
+ * Copyright (C) 2018 Christoph Hellwig
+ */
+
+#include <linux/interrupt.h>
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <asm/sbi.h>
+#include <asm/smp.h>
+#include <asm/softirq_stack.h>
+#include <asm/stacktrace.h>
+
+static struct fwnode_handle *(*__get_intc_node)(void);
+
+void riscv_set_intc_hwnode_fn(struct fwnode_handle *(*fn)(void))
+{
+	__get_intc_node = fn;
+}
+
+struct fwnode_handle *riscv_get_intc_hwnode(void)
+{
+	if (__get_intc_node)
+		return __get_intc_node();
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(riscv_get_intc_hwnode);
+
+#ifdef CONFIG_IRQ_STACKS
+#include <asm/irq_stack.h>
+
+DEFINE_PER_CPU(ulong *, irq_stack_ptr);
+
+#ifdef CONFIG_VMAP_STACK
+static void init_irq_stacks(void)
+{
+	int cpu;
+	ulong *p;
+
+	for_each_possible_cpu(cpu) {
+		p = arch_alloc_vmap_stack(IRQ_STACK_SIZE, cpu_to_node(cpu));
+		per_cpu(irq_stack_ptr, cpu) = p;
+	}
+}
+#else
+/* irq stack only needs to be 16 byte aligned - not IRQ_STACK_SIZE aligned. */
+DEFINE_PER_CPU_ALIGNED(ulong [IRQ_STACK_SIZE/sizeof(ulong)], irq_stack);
+
+static void init_irq_stacks(void)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu);
+}
+#endif /* CONFIG_VMAP_STACK */
+
+#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK
+void do_softirq_own_stack(void)
+{
+#ifdef CONFIG_IRQ_STACKS
+	if (on_thread_stack()) {
+		ulong *sp = per_cpu(irq_stack_ptr, smp_processor_id())
+					+ IRQ_STACK_SIZE/sizeof(ulong);
+		__asm__ __volatile(
+		"addi	sp, sp, -"RISCV_SZPTR  "\n"
+		REG_S"  ra, (sp)		\n"
+		"addi	sp, sp, -"RISCV_SZPTR  "\n"
+		REG_S"  s0, (sp)		\n"
+		"addi	s0, sp, 2*"RISCV_SZPTR "\n"
+		"move	sp, %[sp]		\n"
+		"call	__do_softirq		\n"
+		"addi	sp, s0, -2*"RISCV_SZPTR"\n"
+		REG_L"  s0, (sp)		\n"
+		"addi	sp, sp, "RISCV_SZPTR   "\n"
+		REG_L"  ra, (sp)		\n"
+		"addi	sp, sp, "RISCV_SZPTR   "\n"
+		:
+		: [sp] "r" (sp)
+		: "a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7",
+		  "t0", "t1", "t2", "t3", "t4", "t5", "t6",
+#ifndef CONFIG_FRAME_POINTER
+		  "s0",
+#endif
+		  "memory");
+	} else
+#endif
+		__do_softirq();
+}
+#endif /* CONFIG_SOFTIRQ_ON_OWN_STACK */
+
+#else
+static void init_irq_stacks(void) {}
+#endif /* CONFIG_IRQ_STACKS */
+
+int arch_show_interrupts(struct seq_file *p, int prec)
+{
+	show_ipi_stats(p, prec);
+	return 0;
+}
+
+void __init init_IRQ(void)
+{
+	init_irq_stacks();
+	irqchip_init();
+	if (!handle_arch_irq)
+		panic("No interrupt controller found.");
+	sbi_ipi_init();
+}